Main Entry:

ad·di·tion

Pronunciation:

\ə-ˈdi-shən, a-\

Function:

noun

Etymology:

addicion Anglo-French, from Latin addition-, additio, from addere

Date:

14th century

1: a part added (as to a building or residential section)2: the result of adding : increase3: the act or process of adding ; especially : the operation of combining numbers so as to obtain an equivalent simple quantity4: direct chemical combination of substances into a single product

— in addition

: ²besides, also

— in addition to

: combined or associated with : ¹besides 2